Corrects to show in 2nd paragraph that S&P 500 futures were below fair value

Stock index futures extended losses on Friday after May non-farm payrolls data came in below forecasts.

S&P 500 futures fell 26.4 points and were below fair value, a formula that evaluates pricing by taking into account interest rates, dividends and time to expiration on the contract. Dow Jones industrial average futures slumped 191 points, and Nasdaq 100 futures lost 45 points.

(Reporting by Chuck Mikolajczak; editing by Jeffrey Benkoe)